The territory is due to hold a referendum on independence from France next year amid continued efforts to draw up an electoral roll accepted by all sides.
The UN team will again witness the special French-led commissions, which update the roll that is restricted to long-term residents.
The eligibility of thousands of people had been questioned after they initially failed to prove that they will be allowed to vote.
The vetting process has been marked by claims of the indigenous Kanaks that they would be allowed to cast votes without enrolling.
